Just days after Ford’s announcement of a particle filter-equipped ‘Power Stroke’ diesel engine for large pickup trucks, GM Powertrain said its ‘Duramax’ 6.6L V-8 turbo-diesel engine has been updated – with a filter – too.

Discover B2B Marketing That Performs

Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.

Find out more


There’s a reason for all this activity: stringent federal emissions regulations for diesel engines manufactured from January 2007 which require a 90% reduction in particulate matter and 50% reduction in NOx.


“Maintaining power and torque leadership with the Duramax is important to us because it’s the benchmark that built the engine’s class-leading reputation with our customers,” boasted Charlie Freese, executive director, GM Powertrain Diesel Engineering.


The new Duramax 6.6L V8 engine has increased power and torque for Chevy Kodiak and GMC Topkick medium duty applications. Versions are available with 300 horsepower and 520 lb.-ft. of torque, as well as a new 330-horsepower option with 620 lb.-ft. of torque.


Final advertised ratings for the Chevrolet Silverado and GMC Sierra 2500 and 3500 HD pickups and GM’s full-size vans will announced later.


Upgrades implemented in 2006 enhanced the efficiency, smoothness and quietness of the engine, which GM says was already known as one of the industry’s quietest and strongest diesels.


The engine gets new equipment to help it meet the government-mandated 2007 emissions standard.


The use of reformulated, ultra-low sulphur diesel fuel – which goes on sale nationwide this autumn – is required to meet the new emissions standard. The new fuel’s sulphur content is limited to 15 parts per million (ppm), versus the current standard of 500 ppm. Diesel engines manufactured prior to 2007 can continue to use the current diesel fuel.


To meet the new emissions regulation, the latest Duramax has additional combustion control, including more efficient variable-geometry turbocharging system, cooled exhaust gas recirculation and closed crankcase ventilation to reduce NOx; additional exhaust control, including oxidising catalyst and new diesel particulate filter to reduce soot and particulate matter; increased-capacity cooling system; new engine control software  and uses low-ash engine oil.


An onboard computer controls fuel injection and oxygen content to adjust the exhaust energy to the appropriate level to clean the particulate trap but periodic servicing of the filter is required to remove accumulated ash. The DPF and corresponding components will change the exhaust system length and/or outlet design, depending on the vehicle model. Also, an expanded underbody heat shield is added.


Vehicles used as sweepers, airport ground support, municipal and refuse trucks will likely be most affected by the changes, GM said.


The company also announced it would introduce a new light-duty truck diesel engine after 2009.

Just Auto Excellence Awards - Nominations Closed

Nominations are now closed for the Just Auto Technology Excellence Awards. A big thanks to all the organisations that entered – your response has been outstanding, showcasing exceptional innovation, leadership, and impact.

Excellence in Action
Continental has secured the Window Displays Innovation Award in the 2025 Just Auto Excellence Awards for its Window Projection solution, transforming side windows into dynamic, data-rich canvases. Discover how this compact projection technology and intelligent software are reshaping in-car UX and opening fresh revenue streams for OEMs and mobility providers.

Discover the Impact